Migration for GIF support

[bdickason]

1. Clone/pull down latest version of chicken-server repo
2. Initialize submodule: git submodule update --recursive --remote
3. Update framedata from source: npm update
4. open mysql server
5. add field 'gif' to table attacks
6. run update script: npm run update
7. start server

Success criteria:
On the api/framedata endpoint, there should be a new field called preview_url on every attack

[bdickason]

Mysql commands:

1. use tekkenchicken;
2. ALTER TABLE Attacks_TC ADD COLUMN gif_url VARCHAR(100) DEFAULT NULL;